Py} pep iol r : PROJECT 5.3 FALL-OUT GAMMA RAY INTENSITY | OPERATION IVY i jRepor prepared by: Melvin P, Klein P| ABSTRACT Measurements of the intensity of fall-out gamma radiation as a function of time and distance from the Ivy Mike and King shots are reported, Instruments were placed around Eniwetok Atoll and at several atolis in a southerly semicircle with respect to Eniwetok, Contrary to expectations the winds prevailing at the time of the Mike shot were south or southeasterly and no fall-out gamma radiation with the limits of detectibility was measured at any location other than Eniwetok, The gamma radiation measured on Eniwetok Atoll was considered normal fission fragment radiation which decayed with at7i.2 characteristic, ACKNOW LEDGMENTS Other people beside the author who worked and participated in Project 5.3 are: Richard L. Blumberg, Harold E. Brown and David D, Cudaback, all of UCRL, Livermore, California, Mens. .